Correct selection and scientific use of condoms

Do you know how to use a condom?

During sexual intercourse, is there a good way to enjoy sexual pleasure without causing pregnancy for the woman or contracting sexually transmitted diseases for either partner? In the 17th century, Joseph Condom, the English royal physician, pondered this question and, through repeated experiments, achieved one of the greatest inventions in human history: cutting a sheep's cecum into appropriate lengths, drying it, and softening it with fat and wheat bran until it became a thin, rubbery substance. He presented this invention to Charles II, and this epoch-making product was subsequently named after his surname-Condom. In my country, it is directly translated as "contraceptive condom." This royal patent, through continuous improvement, can now also prolong sexual intercourse and enhance sexual pleasure.

Although condoms have long been available to the general public, benefiting men and women worldwide, not everyone knows how to use them correctly. The following 10 precautions require your careful attention.

(1) Condoms come in different sizes. The appropriate size should be selected according to the size of the penis when erect, and the appropriate thickness should be selected according to the specific situation.

(2) A new condom must be used before each sexual intercourse. Before use, check the production date and expiration date. Expired condoms have deteriorated and are prone to breakage, and should not be used. Condoms must be stored in a cool, dry environment away from acids, alkalis, and oils. If they become sticky or brittle after exposure to these conditions, they should not be used even if they are within their expiration date.

(3) Carefully tear open the individually sealed packaging bag before use, and avoid using sharp tools such as scissors.

(4) Before putting on the condom, pinch the small air reservoir at the tip to prevent the air in the reservoir from expanding when heated, causing semen to leak out during ejaculation. The condom should not be unfolded beforehand; it should be put on after the penis is fully erect, and some space should be left at the front of the condom after it is put on.

(5) Unfold the condom downwards from the head of the penis; otherwise, the condom will have extra wrinkles and may slip off easily. Also, it's best to put on the condom just before penetration after foreplay; putting it on too early will cause it to dry out and be difficult to insert. However, you shouldn't remove the condom just before ejaculation, as this increases the chances of pregnancy for the woman. Again, it must be put on before intercourse begins, ensuring it covers the entire penis and that the rolled-up end is exposed.

(6) Only water-based lubricants can be used on condoms. Vaseline, liquid paraffin, face cream, cooking oil, etc. can all increase the brittleness of condoms in a short time and accelerate their breakage.

(7) If a condom is found to be broken or slipped during use, sexual intercourse should be stopped immediately. To prevent infection, the genitals should be cleaned with disinfectant. Simply changing the condom is not safe.

(8) After ejaculation, before the penis becomes flaccid, hold the bottom of the condom with your fingers and pull it out along with the penis. When removing the condom, do not allow semen to leak out, and do not allow vaginal secretions on the outside of the condom to come into contact with the body. Each condom is for single use only, and used condoms should be put into a plastic bag and thrown into the trash can.

Water-based lubricants: Primarily composed of water, glycerin, cellulose, and carrageenan. Their advantages include not dissolving latex, allowing for use with latex condoms without causing them to break. Additionally, they are highly soluble, have strong biocompatibility, and are easy to wash off. The disadvantage is that they are relatively volatile.

(9) Do not touch the female genitals with your fingers after removing the condom. You must wash your hands with soap under running water immediately.

(10) If semen enters the vagina, use emergency contraception immediately.

It is important to note that even with correct condom use, it is still possible to contract sexually transmitted infections (STIs). According to the *New England Journal of Medicine*, the failure rate of condom use in preventing HIV is 16.7%; the *Social Science in Medicine* reported a failure rate of 31%; and multiple medical and government agencies, including the National Institutes of Health (NIH) and the Food and Drug Administration (FDA), have jointly stated that there is no scientific evidence that condoms are effective in preventing most STIs. This is because the natural latex used in condoms has natural cracks between 5,000 and 70,000 nanometers, while the HIV virus is approximately 120 nanometers in diameter. Therefore, practicing safe sex is the only correct way to prevent STIs.

Note: In my country, condoms are typically categorized into large, medium, and small sizes. The large size has an opening diameter of 35 mm, the medium 33 mm, and the small 31 mm. Regarding width, according to international standards, the condom is stretched out flat and its midsection measured: large 55 mm, medium 52 mm, and small 49 mm. Most men can directly purchase a medium size. Alternatively, they can wrap a thin string around the midsection of a fully erect penis, measure the string length (penis circumference), divide by 3.14 to obtain the penis width, and then purchase the condom closest to their measurements. Purchasing the wrong size may result in the condom slipping off inside the vagina due to being too large, reducing its contraceptive effectiveness; or it may be too small, obstructing blood circulation and causing premature ejaculation, failure to ejaculate, or the condom breaking and allowing semen to enter the vagina.

Condoms mainly come in three types: ultra-thin, thin, and regular. Ultra-thin condoms are 0.03 mm thick, regular condoms are 0.04-0.06 mm thick, and thin condoms fall in between. The thicker the condom, the lower the sensitivity of the male penis during intercourse, leading to a perceived greater distance between the man and his partner, and naturally, a less pleasurable experience. This is similar to how no one likes wearing thick gloves to handle objects. However, ultra-thin condoms are not suitable for everyone. For men who ejaculate quickly, are older, or have poor self-control, thicker condoms are preferable, as they can help prolong ejaculation time.